How to access and edit Mapping Node via python?
bpy.data.materials['Material'].node_tree.nodes['Cracks_Mapping'].rotation[2] = some value


That's how you do it. input[0] is the only input of the node, the Vector. The 0 is the index. For example rotation has 3 index, 0, 1, and 2 for X, Y, and Z. Knowing that, if you assign a value to .rotation[2] like in my code example you'll modify Z rotation value of the mapping node. It's pretty straightforward really.